1. Field of the Invention
The present invention relates to the navigation of electronic documents using a touchscreen display.
2. Background of the Related Art
The advent of the personal computer (PC) in the latter half of the twentieth century led to the widespread use of electronic devices to digitally store and process information. The technologies used in computers and other electronic devices have continued to advance, aided by economies of scale, and with ongoing reinvestment in product research and development. Factors such as increasing miniaturization and related improvements in memory density and processor speed, along with vastly improved electronic displays and user input peripherals, have led to the development of many different electronic consumer products. Modern electronic devices are now capable of storing large amounts of information in digital form, even on very compact, lightweight, and portable devices. Popular portable electronic devices with built-in or otherwise connected display screens currently include laptop computers, tablet computers, smartphones, digital music players, and handheld electronic game consoles.
Numerous uses for electronic devices have been developed to harness the ability of electronic devices to store and retrieve large amounts of information. In particular, this aspect of digital storage is commonly used for creating and storing electronic documents that may then be viewed on an electronic display. Electronic documents may be created from scratch, such as by using a word processor. Existing, paper-based documents may be converted to an electronic format, such as by electronically scanning them. Digital cameras are also commonly used to generate digital photographic images. Even complete books are now being digitized and stored in an electronic format as an alternative to carrying around physical, bound paper volumes. An example of a device that can be used to store and display books is referred to as an e-book reader, which is dedicated to the purpose of displaying electronic copies of books. The ability to store and display electronic copies of books that can be displayed page-by-page on a screen is also being emulated using software applications on devices that are not restricted to that function, such as on portable computers and smartphones.
The power and portability of electronic devices makes the use of electronic documents preferable, in many ways, to that of traditionally-bound paper-based documents, such as books, newspapers and other periodicals, and bound photo albums. For instance, the compact size and low weight of e-book readers, portable computers, and smartphones capable of storing and displaying electronic copies of books is competitive with that of traditional, paper-based media. Additionally, the built-in memory on portable electronic devices is now large enough that many documents may be stored on a single, portable device. Devices with Internet-browsing capabilities also have potential access to a virtually unlimited number of remotely-stored documents. Despite these advances in electronic document storage and viewing, however, most portable electronic devices are limited to having a single, rigid display on which to view selected pages of documents. Ongoing efforts are being made, therefore, to improve user interfaces on these devices for navigating electronic documents.